Monthly Archives: October 2001

Temoporfin-mediated photodynamic therapy represents a major advance in the treatment of head and neck cancer, yielding complete response rates comparable with those published for surgery or radiotherapy, according to phase II data reported here last week during ECCO 11, the European Cancer Conference.

Temoporfin-mediated photodynamic therapy (Foscan PDT) is an “effective and well-tolerated treatment” and can be administered without surgery, said Dr. Colin Hopper, a consultant surgeon of the National Medical Laser Centre in London, UK. Dr. Hopper presented the results of a prospective non-randomised phase II study, conducted in 15 centers in 6 countries. The trial examined response rates to Foscan PDT in 114 patients with primary (Tis, T1 and T2) squamous cell carcinoma of the lip, oral cavity, oropharynx or hypopharynx.

Patients with Karnofsky status greater than or equal to 70 received Foscan (0.15 mg/kg IV), followed 4 days later by a single nonthermal illumination of the tumor with red light (20 J/cm?, irradiance 100 mW/cm? , wavelength 652 nm). The initial response was determined after 12 weeks. After 2 years of follow-up, 85% of patients had a complete response (elimination of the tumor) with Foscan PDT alone, and another 6% achieved a complete response with Foscan PDT followed by other adjunctive therapy, including surgery or radiotherapy, giving an overall response rate of 91%. Dr. Hopper reported that in 59% of all cases a complete response rate was biopsy-confirmed. The 1- and 2-year overall survival rates were 90% and 81% respectively, he said. There were 23 non-fatal serious adverse events of which only 5 were related to the treatment (two burns, one photosensitivity reaction, one excessive tissue necrosis, and one increase in pain and dysphagia). Twelve patients died during the first year, but their deaths were not associated with the treatment, the British researcher said. Dr. Hopper explained that “these response rates are comparable to those published for surgery or radiotherapy, but photodynamic therapy has the advantage of not being associated with the major toxicity of radiotherapy nor the tissue loss associated with surgery. It produces excellent cosmetic results, preserving form and function, and does not compromise future treatment options for recurrent, residual or second primary disease.” This is particularly important, because there is a significant risk in head and neck cancer that another cancer will develop at or near the original site, and will require such treatment, he noted.

The most common adverse event noted was local pain at the treatment site, but according to the physicians involved in the study, “this can be managed with standard analgesic treatment.”

Yale School of Medicine researchers have found that a diet high in cholesterol, animal protein and vitamin B12 is linked to risk of a specific type of cancer of the stomach and esophagus that has been increasing rapidly.

The researchers also found that plant-based nutrients such as dietary fiber, dietary beta-carotene, folic acid, vitamin C and vitamin B6 were associated with lower risk of these kinds of cancers. They further found that regular use of vitamin C supplements was associated with a 40 percent reduction in the risk of cancer in the middle and lower parts of the stomach.

The rate of a specific type of esophageal and stomach cancer, known as adenocarcinoma of the esophagus and gastric cardia, has increased by 300 percent since the mid-1970s, according to lead author Susan Mayne, associate professor in the Department of Epidemiology and Public Health at Yale School of Medicine, and associate director of the Yale Cancer Center. To identify reasons for this rapid increase, the United States National Cancer Institute launched a large study at three centers, including Yale, the University of Washington and Columbia University.

The researchers interviewed patients throughout Connecticut, New Jersey and western Washington State and compared the nutrient intake of 1,095 people with stomach or esophageal cancer to that of 687 healthy people in a control group. The team also looked at the participants’ use of nutrient supplements. Their results are published in the October issue of Cancer Epidemiology, Biomarkers & Prevention. “We found that many animal-based nutrients found in foods of animal origin are strongly associated with risk of developing these types of cancers and we were able to identify nutrients that presumably would be protective,” said Mayne. “We also found that regular users of vitamin C supplements were at significantly lower risk of stomach cancer.”

In a separate analysis of these data, the research team found that obesity is strongly linked with risk of these cancers. “The increase in the prevalence of obesity in the United States certainly contributes to the time trends,” said Mayne. “Our results suggest that prevention strategies for these cancers should emphasize increased consumption of plant foods, decreased consumption of foods of animal origin with the possible exception of dairy products, and control of obesity.”

Other researchers on the study include Principal Investigator of the Yale site Harvey A. Risch and Robert Dubrow at Yale; A. Brian West, previously at Yale and now at New York University Medical Center; Wong-Ho Chow and Joseph F. Fraumeni, Jr. of the U.S. National Cancer Institute; Marilie D. Gammon, previously at Columbia University and now at the University of North Carolina; Habibul Ahsan and Heidi Rotterdam of Columbia University; Janet B. Schoenberg, from the New Jersey Department of Health and Senior Services; Thomas L. Vaughan, Diana C. Farrow and Janet L. Stanford from the University of Washington; and William J. Blot from the International Epidemiology Institute.

Note: This story has been adapted from a news release issued by Yale University for journalists and other members of the public.

A cup of black raspberries a day may help keep esophageal cancer at bay. Researchers found evidence in rats that black raspberries may both prevent the onset of esophageal cancer as well as inhibit precancerous growth already underway. “Black raspberries are loaded with nutrients and phytochemicals that may prevent the development of cancer,” said Gary Stoner, a study co-author and a professor of public health at Ohio State University.

Stoner, who has also found similar anti-carcinogenic effects with strawberries, said the study results suggest that a daily diet of about 1.4 to 2 cups of fresh berries may be ideal for staving off certain types of cancer. “Although this level is larger than a standard serving size of fruit, it is behaviorally possible,” he said. “The National Cancer Institute recommends that every American eat at least four to six helpings of fruit and vegetables each day. We suggest that one of these helpings be berries of some sort.” The research appears in the journal Cancer Research.

Esophageal cancer is the sixth-leading cause of cancer-related deaths worldwide. The outlook is bleak for those diagnosed with the disease,
five-year survival rates range from 8 to 12 percent.

In the current study, the researchers looked at black raspberries’ ability to halt the onset of cancer, as well as the fruit’s ability to inhibit the progression of precancerous cells to cancer. They conducted experiments on two groups of rats. Some of the rats from each group were injected with NMBA, a chemical carcinogen that induces esophageal cancer. NMBA is one of a group of chemicals called nitrosamines, compounds that have been linked to cancer. Nitrosamines are found in fried bacon, cured meats, tobacco products, beer and certain industrial products.

Rats in the study received NMBA and their diet in a variety of combinations. Some rats were fed a regular diet without raspberries, while others received diets consisting of 5 percent or 10 percent black raspberries. Some were fed raspberries only after receiving NMBA, while others were fed the raspberry diet before and after the injection with the carcinogen. Feeding the rats 5 and 10 percent black raspberries before and after NMBA treatment reduced the number of tumors per rat by 39 and 49 percent, respectively, when compared to animals not fed black raspberries. The fruit also hindered the development of esophageal cancer in individual rats fed black raspberries after NMBA treatment. By week 15 of the study, diets of 5 and 10 percent black raspberries appeared to decrease tumor occurrence and size. At week 25, diets of 5 and 10 percent black raspberries had reduced the number of tumors by an average of 62 percent and 43 percent, respectively. By week 35 of the study, a diet of 5 percent black raspberries had reduced the number of tumors per animal by 66.5 percent, compared with NMBA-treated control mice fed a regular diet.

“When berries were fed to the rats that had been pretreated with NMBA, the diet containing 5 percent black raspberries seemed to inhibit cancer to a greater degree than did a diet of 10 percent berries, a finding that has also emerged in other studies,” Stoner said. “There are certain compounds in berries – and other fruits and vegetables – that in very high doses may actually promote the cancer process. This certainly doesn’t mean to stop eating fruits and vegetables, but don’t overdo it.”

Scientists know that certain foods contain compounds that are likely to protect against specific types of cancer. Past studies suggest that tomatoes help protect against prostate cancer, and that tea consumption may reduce the risk for esophageal cancer. But the mechanism of prevention is still somewhat of a mystery.

Raspberries are chock full of compounds with potentially anti-carcinogenic effects, including vitamins, minerals and plant nutrients such as anthocyanins – strong antioxidants that give berries their color. “We’re currently looking at berry extracts and testing the ability of these extracts to inhibit the development and progression of cancer,” Stoner said. “As we identify these extracts, we will then try to pinpoint the specific compounds in them that help inhibit cancer.”

In the current study, Stoner and his colleagues tested the effects of ellagic acid – a plant nutrient shown to have protective effects against esophageal cancer. Berries are rich in ellagic acid. But the researchers found that ellagic acid alone could not account for the fruit’s ability to inhibit cancer. “One or more additional berry components are undoubtedly contributing to the fruit’s anti-cancer effects,” Stoner said. He chose black raspberries for this study because previous studies had shown that ellagic acid inhibited carcinogen-induced esophageal and colon cancer in animals. He and his colleagues then tested a series of fruits for their ellagic acid content, finding that berries contained the highest amount.

“We then decided to take a food-based approach to cancer prevention and began testing the berries’ ability to inhibit chemically-induced esophageal and colon cancer,” Stoner said. “Sure enough, we found that freeze-dried berries were highly protective in the esophagus and colon. But we also found that they were ineffective in protecting against lung cancer. “The protective compounds in berries may not be absorbed into the blood stream and delivered to the lungs in high enough amounts to be protective. We do believe that they protect the esophagus and colon because they are absorbed by these organs as the food moves through the digestive tract.”

The study was funded by a grant from the Ohio Department of Agriculture and the National Cancer Institute.

Stoner co-authored the study with Laura Kresty, Mark Morse, Peter Carlton, Ashok Gupta, Michelle Blackwood and Charlotte Morgan, all of Ohio State, and Jerry Lu of the M.D. Anderson Cancer Center at the University of Texas.

Note: This story has been adapted from a news release issued by Ohio State University for journalists and other members of the public. If you wish to quote from any part of this story, please credit Ohio State University as the original source.

It’s not every day a dentist gets to play Star Wars. But that’s not why more than 30,000 dentists in the United States are deploying OralCDx, a new diagnostic tool that incorporates technology developed as part of the Strategic Defense Initiative. OralCDx, launched nationwide last year, offers dentists a better shot at catching oral cancer lesions while there’s time to treat them.

About 8,000 Americans die of oral cancer each year. Nearly 30,000 new cases are diagnosed annually, and only 53 percent of all oral cancer victims are still alive five years after diagnosis. But among those in whom the disease — which is most common among tobacco users and heavy drinkers and is more common among men, people over 40 and African Americans — is caught early, five-year survival rates soar to 88 percent.

The problem has been that early stage oral cancer lesions look like benign mouth lesions, even to vigilant dentists. By the time a lesion becomes obviously, visibly cancerous, successful treatment is difficult.

In the past, dentists have had to make tough choices: Should they perform traditional scalpel biopsies (or refer patients to oral surgeons for the procedure) on all of the estimated 5 percent to 15 percent of their patients who have oral lesions? At up to $300 per procedure, plus lab analysis fees of up to several hundred dollars, scalpel biopsy is costly. Plus, the procedure requires the uncomfortable surgical removal of chunks of tissue, and only a small number of the lesions caught in this net turn out to be cancerous.

OralCDx, produced by New York-based OralScan Laboratories Inc., helps dentists determine which lesions warrant a biopsy. When faced with a lesion that is even remotely suspicious, the dentist gathers three layers of tissue with a device that looks a bit like a tiny toilet brush. Having completed this painless procedure, he swabs a slide and mails it off to OralCDx.

The software at the heart of the OralCDx system is adapted from a program designed for the Strategic Defense Initiative, the ambitious missile defense system championed by President Reagan in the 1980s. With it, OralCDx can spot a cancerous cell even if it is partially obscured by other cells, much in the way that the SDI system is supposed to sort decoys from real missiles. Having identified, with the computer’s help, any suspicious cells, the OralCDx pathologist faxes a report to the dentist, who can either proceed with a scalpel biopsy or tell the patient to rest easy.

At $65 for the lab work plus the typical procedure fee of $100 to $150 charged by the dentist (who gets the test kits for free from OralScan), the new system might be pricey for the 108 million Americans without dental insurance. OralScan points out, though, that many medical insurance plans cover the cost.

While the SDI’s ability to distinguish real targets from decoys remains unproven, OralCDx, which received an American Dental Association Seal of Acceptance in October, is backed by a study published in the Journal of the American Dental Association in 1999. In that study, the system accurately detected 100 percent of the cancerous and precancerous lesions included in the trial and even picked up signs of cancer lesions that clinicians hadn’t considered suspicious.

No word so far, though, as to whether OralCDx can be fooled by Mylar balloons.